RAS question
India receives most of its rainfall from:
Correct answer: (A) Southwest monsoon (about 70-80% of annual rainfall).
India receives most of its rainfall from the southwest monsoon, which brings about 75-80% of the country's annual rainfall during June-September.
Explanation
The southwest monsoon is India's main rainfall system because it is the June-September monsoon season that supplies roughly three-fourths of the country's annual rain. IMD's Monsoon 2025 report describes the Indian summer monsoon season as the principal rainy season over much of the Indian subcontinent and says it contributes nearly 75-80% of India's annual rainfall. The southwest monsoon provides about 75% of annual rainfall, while the northeast monsoon contributes only about 10-15%, mainly over Tamil Nadu. Western disturbances and tropical cyclones add smaller, episodic contributions, so they cannot account for most all-India rainfall.
Why the other options are wrong
- (B) The northeast monsoon contributes only about 10-15% of annual rainfall and is mainly important for Tamil Nadu, so it is not India's dominant all-India rainfall source.
- (C) Tropical cyclones are occasional systems and account only for part of the remaining rainfall after the monsoon contribution, not the bulk of India's annual rainfall.
- (D) Western disturbances contribute only about 5-10% of annual rainfall, far below the southwest monsoon's roughly three-fourths share.
Concept
This tests the Indian climate and monsoon section of the RAS geography syllabus. It recurs because rainfall sources, seasonality, and regional dependence on monsoon winds are basic to agriculture, water resources, and disaster questions.